The present invention relates to secondary containment systems and especially, although not exclusively to a piping construction and a system for housing secondarily contained piping above-ground and underwater for hydrocarbon storage and delivery systems.
A secondary containment system is one which functions to collect and contain the fluids leaking out of another (primary) containment system. For example, a primary containment system may store and deliver gasoline at a filling station. A secondary containment system would collect and contain the same gasoline if a primary delivery pipe should rupture or otherwise spill the gasoline. Secondary containment systems have been developed to overcome the environmental problems that have been encountered with respect to leakage of hazardous fluids from tanks and pipe lines. As indicated, this can be a particular problem with respect to underwater installations in which undetected leakage of hazardous fluids into the surrounding water over long periods of time can produce harmful conditions for both sea life and human beings, as well as extensive pollution which is difficult and expensive to clean.
Today there is also great public concern with above-ground piping, because chemicals are penetrating into underground water supplies, contaminating public drinking water and making some of the food supply unusable, among other things. The entire environment may be in the process of being degraded to a serious level which tends to cast doubt on the future availability of safe water. Therefore, many government agencies have enacted, and continue to enact laws which require a secondary containment system designed to capture and contain the spilled gasoline or other liquid materials in order to prevent them from leaking into the earth below any above-ground piping, or into the water surrounding underwater piping. The captured gasoline or other liquid material may then be pumped out of the secondary container for proper disposal. This eliminates the possibility of gasoline spillage to contaminate surrounding water or underground water supply.
Manufacturers of containment systems have responded by developing and producing a variety of secondary containment systems for conventional underground piping which are designed to contain and prevent any leakage from escaping into the environment. Many of these systems have proven to be effective containment systems but have been found to be difficult and costly to install.
In addition, these systems are not applicable for use in above-ground or underwater installations. These particular installations have special considerations which include, but are not limited to: piping flexible enough to bend around existing structures and/or sea terrain; both the primary and secondary piping should be removable for repairs and/or replacement; the primary and secondary piping should be protected from external damage, and from degradation from ultraviolet rays; the piping system should be waterproof; and the piping should be strong enough to be protected from external loads such as boat props and the like.
It can be very difficult and expensive to meet all of the many different environmental and safety standards at a reasonably acceptable cost, particularly in light of the many state and local governments writing individual laws that impose a wide variety of standards which the manufacturers of such systems must meet.
Accordingly, an object of the invention is to provide a new and improved secondary containment system which will draw all spilled fluids that may leak from a primary supply pipe to a preselected collecting point which may be monitored. It is a further object of the present invention to provide a system for housing such a secondary containment system. Still further, it is an object of the present invention to provide such a housing system which is flexible, yet provides rigidity and protection against fire. Yet still further, it is an object of the present invention to provide such a housing system which allows for both the primary and secondary piping to be removable for repairs and/or replacement. It is another object of the present invention to protect the primary and secondary piping from external damage, and from degradation from ultraviolet rays. It is yet another object of the present invention to provide such a housing system which is waterproof. Still further, it is another object of the present invention to provide a housing system which is strong enough to be protected from external loads such as boat props and the like.
A further object of the present invention is to provide a practical secondary containment system within a housing system which may be manufactured in a factory, shipped and installed at a reasonably low cost in a fully usable manner; and yet one which meets all requirements of the environment within which it must be used. It is a further object of the present invention to provide an economical, easily installed, highly durable and environmentally secure flexible piping system within a housing system.